Collector coolant system



July 16, 1963 1.. 'r. ZlTELLl COLLECTOR CCOLANT SYSTEM Filed July 21. 1960 r 08 f w 2 m Uite States This invention relates in general to electron tube apparatus and in particular to a novel cooling system of the type employed in cooling the electron collector of an electron beam tube as, for example, a high power klystron tube or traveling wave tube.

In the art of high frequency electron beam tubes, extremely high powers are being developed, for example, high power klyst-ron tubes in a range of 0.400 to 0.450 kilomegacycle are now in use which produce peak output powers of 1.25 megawatts and average power outputs of 75 kilowatts. With this great amount of power output it can be readily seen that the amount of heat to be dissipated becomes more than substantial. Cooling systems become increasingly important in order to prevent the electrons which bombard the collector from rapidly burning through the collector and letting the tube down to atmospheric air pressure.

Accordingly, it is the object of this invention to provide a novel cooling system for the collector of a high power electron beam tube.

One feature of the present invention is the provision of an array of longitudinally directed cooling channels formed on the outside surface of the beam collector member and defining with a cover member a longitudinally partitioned coolant annulus, the channels being interconnected such that the coolant flows in opposite directions in adjacent channels to obtain efiicient cooling of the collector with a minimum of parts.

Other features and advantages of this invention will become apparent from perusal of the specification taken in connection with the accompanying drawings, wherein:

FIG. 1 is an isometric view partly broken away showing the coolant channels for flowing cooling fluid around the collector,

FIG. 2 is a longitudinal cross-sectional view of the structure of FIG. 1 taken along line 2-2 in the direction of the arrows, and

FIG. 3 is a fragmentary transverse cross-sectional view of the collector assembly of FIG. 2 taken along the line of 3-3 in the direction of the arrows.

Referring now to the drawings, the collector and novel cooling system of the present invention comprise an openended cylindrical collector 11 as of copper, for example, closed 01f at one end. Formed as by machining into the exterior walls of collector 11 are a plurality of narrow, deep, parallel, longitudinally directed channels 13 which form therebetween a number of short, thick fins 12 and 12' extending over most of the length of the collector 1 1. Pins 12', which comprise every alternate fin completely around the periphery of collector 11 are slightly shorter than fins 12 which are adjacent to fins 12' and extend the entire length of the collector 11. This arrangement provides connecting channels between pairs of adjacent channels 13.

Formed as by machining into the closed end of cylindrical collector 11 are a number of outwardly radiating channels 15, similar to channels 1 3, and communicate with alternating channels .13.

Closely fitting over the fins 12 and 12' as by heliarc welding, for example, is a hollow, open-ended cylindrical jacket 16 which extends slightly past the ends of collector 1'1. Closely fitted over the fins defined by the channels 15 in the closed end of cylinder 11 is an apertured atent "ice 2 partition disc 17 brazed to the fins 15' and to the inner diameter of outer jacket 16 near the closed end. Formed in the periphery of partition disc 17 are found a number of slots 17 which are aligned with alternate channels 13' of cylindrical collector 11 and are adjacent to the channels =13 communicating with channels 15 in the closed end of collector 11.

Closely fitted over the open end of collector 11 is a centrally apertured disc 22, brazed thereto, which is sealed to the inner diameter of the open end of outer jacket 16. Disc 22 further communicates with and is sealed to fins 12.

-It is noted that the term open end used in describing the present invention defines the end of the structure in which the electron beam enters and closed end defines the opposite end of the structure.

Carried on the closed end of the outer jacket 16 is a fluid distribution manifold 18 sealed to the inner diameter of the closed end of jacket 16. Manifold 1'8 distributes and collects fluid for the coolant system of collector 11 and includes a central aperture 19 and an offset aperture 21 as a fluid inlet and a fluid outlet, respectively. When manifold 18 is sealed into position, a first fluid distributor chamber 25 is for-med, communicating with alternate channels 13 through slots '17 in partition disc 17 on one end and with offset aperture 21 on the other side. A second fluid distributor chamber 26 is also formed, communicating with channels 15 on one end and with central aperture 19 on the other.

During operation the cooling fluid, normally water, enters distributor manifold 18 through aperture 19 into the first distributor chamber 26. The coolant then passes through the channels 15 in the enclosed end of collector 11, along coolant channels 13 to the end of collector 11, across connecting channels 10 and then back along adjacent channels 13 into the distributor 25 through slots 17 in partition disc '17, and thence out aperture 21. It is noted that whether the fluid enters into aperture 19 or 21, as shown in the direction of the arrows in FIG. 2, is purely a matter of choice and can be reversed.

It is further noted that making the size of the fins deeper will not affect better cooling because of the rapid temperature drop along the length of the fin while making them wider would decrease the metal to surface area. Therefore, the optimum geometry exists when the fins are approximately equal in depth and width. It is also noted that the width of channels 13 are less than the width of cooling fins 12 and 12'. The collector features including, fins of approximately equal depth and width with narrow channels therebetween, and the radial distribution of coolant channels on the end wall of the collector are all claimed in a copending application of Robert S. Symons, U.S. Serial No. 39,168, filed June 27, 1960, and assigned to the assignee of the present invention.

Since many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In a collector for dissipating the energy of a high velocity beam of charged particles including; a tubular collector for receiving the beam incident therein; a plurality of cooling fins on the outer surface of said collector, said cooling fins being of approximately equal width and depth; said cooling fins defined by a plurality of peripherally spaced-apart longitudinally directed channels, said channels having a width less than the width of said cooling fins; a connecting channel for connecting adjacent pairs of said longitudinally directed channels; a tubular jacket surrounding said cooling fins; said longitudinally directed channels, said connecting channel, said fins and said jacket defining cooling annulus; and means for distributing an inlet and outlet flow of coolant fluid to said cooling annulus.

2. The apparatus according to claim 1 wherein said tubular collector is closed at one end, said closed end including a plurality of outwardly directed channels radiating from the center of said closed end, said outwardly radiating channels communicating with alternate longitudinal channels, said outwardly radiating channels and said alternate longitudinal channels defining an input cooling channel and said adjacent longitudinal channels defining an outlet cooling channel, and distributor means for distributing a coolant through said cooling channels.

References Cited in the file of this patent UNITED STATES PATENTS 2,487,078 Sloan Nov. 8, 1949 2,741,718 Wang Apr. 10, 1956 2,888,584 Hickey May 26, 1959 2,928,972 Nelson Mar. 15, 1960 

1. IN A COLLECTOR FOR DISSIPATING THE ENERGY OF A HIGH VELOCITY BEAM OF CHARGED PARTICLES INCLUDING; A TUBULAR COLLECTOR FOR RECEIVING THE BEAM INCIDENT THEREIN; A PLURALITY OF COOLING FINS ON THE OUTER SURFACE OF SAID COLLECTOR, SAID COOLING FINS BEING OF APPROXIMATELY EQUAL WIDTH AND DEPTH; SAID COOLING FINS DEFINED BY A PLURALITY OF PERIPHERALLY SPACED-APART LONGITUDINALLY DIRECTED CHANNELS, SAID CHANNELS HAVING A WIDTH LESS THAN THE WIDTH OF SAID COOLING FINS; A CONNECTING CHANNEL FOR CONNECTING ADJACENT PAIRS OF SAID LONGITUDINALLY DIRECTED CHANNELS, A TUBULAR JACKET SURROUNDING SAID COOLING FINS; SAID LONGITUDINALLY DIRECTED CHANNELS, SAID CONNECTING CHANNEL, SAID FINS AND SAID JACKET DEFINING COOLING ANNULUS; AND MEANS FOR DISTRIBUTING AN INLET AND OUTLET FLOW OF COOLANT FLUID TO SAID COOLING ANNULUS. 